This disclosure relates to multilayered polyolefin films, methods of manufacture thereof and to articles comprising the same.
Multilayered films are widely used as heavy duty shipping sacks for bagging bulk products such as chemicals, polymers, fertilizers and animal food. These multilayers are often polyethylene based, combining high density polyethylene (HDPE) as stiffening layer and metallocene linear low density polyethylene (LLDPE) sealant layer for sealability and toughness. Combinations of different type of polyethylenes layers and proper layer ratio selection offers desirable properties such as stiffness for mechanical strength and machineability (i.e., bag filling operation), toughness (good machine direction tear and dart drop) and sealability (good heat seal property). For polyethylene based multilayered films, incorporating more HDPE increases stiffness. However, the tear resistance in the machine direction (MD) is reduced. There therefore exists a need for improved high stiffness, high toughness multilayer films and heavy duty packaging in order to reduce the multilayered film thickness.